RE: [PATCH v2] iommu/vt-d: Allocate DMAR fault interrupts locally

[Tian, Kevin]

> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Monday, April 8, 2024 3:22 PM
> 
> On 2024/4/8 14:54, Tian, Kevin wrote:
> >> From: Dimitri Sivanich <sivanich@xxxxxxx>
> >> Sent: Friday, March 22, 2024 4:51 AM
> >>
> >> The Intel IOMMU code currently tries to allocate all DMAR fault interrupt
> >> vectors on the boot cpu.  On large systems with high DMAR counts this
> >> results in vector exhaustion, and most of the vectors are not initially
> >> allocated socket local.
> >>
> >> Instead, have a cpu on each node do the vector allocation for the DMARs
> on
> >> that node.  The boot cpu still does the allocation for its node during its
> >> boot sequence.
> >>
> >> Signed-off-by: Dimitri Sivanich <sivanich@xxxxxxx>
> >
> > Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
> >
> 
> Kevin,
> 
> Jacob has another proposal which shares the irq among all IOMMUs.
> 
> https://lore.kernel.org/linux-iommu/20240403234548.989061-1-
> jacob.jun.pan@xxxxxxxxxxxxxxx/
> 
> How do you like this?
> 

I'm a bit concerning about the need of looping all IOMMU's in DMAR
irqchip mask/unmask handlers. this one sounds simpler to me.